Amniocentesis Q & A
Saturday, April 28, 2007
Kenneth F. Trofatter, Jr., MD, PhD
Whenever a woman is considering a genetic amniocentesis during pregnancy, usually one or more of the questions below are among those on her mind. Although the answer to these will vary by provider, let me give you my typical responses:
· “Do you have to stick the baby?” – No, we try to avoid that by looking with the ultrasound while we are doing the procedure. We are actually going to take some of the fluid (about 2/3 oz) from around the baby. The fluid is mostly fetal urine (“baby pee”) at this point in the pregnancy and it contains cells from the baby that we can then grow in the laboratory to determine the baby’s chromosomes. After we get done, the fluid around the baby will look no different to you and the baby will quickly replace the small amount we have removed.
· “Does it hurt? (usually phrased as “My friend told me this REALLY hurts!?!”)” - Usually it is SO painful that we have to have several large nurses sit on you while I do the procedure! No, seriously, we use a very thin needle, thinner than the one they use to draw blood or start an IV. You will probably not feel it much at all as I go through the skin and you will probably feel a cramp, like a menstrual cramp, when I go into the uterus. I will warn you when I am going to do that. You can have someone hold your hand while I am doing the procedure if you would like. Most folks say when it's over that "it wasn't as bad as I thought it was going to be."
· “Are you going to numb me up?” – I can if you would like, although I usually do not and hardly ever have since we started using these thin needles about 20 years ago. The numbing medicine usually hurts more than the needle stick and I can’t numb the uterus to stop the cramp I told you about. Also, if the baby moves, then I might have to stick you 3 or 4 times rather than just once.
· “What are the risks of the procedure? (usually phrased as “My baby moves a lot, what will happen if he/she gets stuck with the needle?”)” – The risk of losing the baby as a result of the procedure is less than 1 in 1000. Other risks include the possibility of breaking the bag of waters, that may or may not lead to delivery or other complications (which I usually do not discuss unless the patients asks at this point), the risk of introducing infection into the uterus, although this is so rare that we do not use any antibiotics to do this procedure and, to help prevent that, we clean your abdomen off first with an antiseptic solution (cold, wet, and scratchy, runs all over the place - the worst part of the procedure) and use sterile drapes (so please do not try to help me with this procedure), and the risk of bleeding either from the placenta if we have to insert the needle through that to get to the fluid, or from the baby, either because of hitting a fetal-placental blood vessel or the baby’s umbilical cord. Again, we try to avoid the latter events by watching with the ultrasound while we do the procedure; even if we do get some bleeding, which is not uncommon when we go across the placenta, it usually stops very quickly and we will watch it until it does. If you are Rh-negative, we will give you Rh-immune globulin after the procedure to help prevent ‘sensitization’ unless you know the baby’s father is Rh-negative too. (I usually do not discuss the possibility of isoimmunization in general unless the mother is Rh-negative or there is substantial bleeding afterwards). I will also be trying to avoid hitting the baby and plan, intentionally, to place the needle away from the baby’s head, but if the baby does move and hit the needle, I will tell you what part of the baby got hit so that we can follow up after the baby is born. Usually there are no long term consequences of this.
· “If I do this test, will it tell me that I am going to have a normal baby?” – That is not an easy question to answer. Chances are, if the chromosomal studies are normal, and we don’t see any abnormalities of the baby, the odds are in your favor the baby will be ‘normal.’ There are rare circumstances when the baby will have a chromosomal problem that is not picked up by the studies or a genetic problem that we did not know about so that we could look, specifically, for it. Other things can also happen during the pregnancy, unrelated to the amniocentesis that could cause the baby not to be ‘normal’ as well.
· “How long does it take to do? (usually phrased as “How long is that needle going to be in me!?!”)” – It usually takes me longer to clean and drape your abdomen than it does for me to do the procedure. Once the needle is in the uterus, it takes about 30 seconds to draw off the fluid because the needle is so thin.
· “How long before I get the results back (usually phrased as “You mean I am NOT going to find out today if my baby’s alright!?!”)” – If we see nothing wrong with the baby, or if you do not have a risk for a specific chromosomal abnormality, such as Down syndrome or trisomy 18 based on other studies, it usually takes 10 to 14 days to get the final results. We can do a rapid screen called FISH (fluorescent in situ hybridization) for a limited number of specific chromosomal abnormalities if one of these is suspected. The results of FISH are usually back within 72 hours, but it does not screen for all chromosomal abnormalities, so routine cultures are also done and you will still have to wait 10-14 days to be completely reassured. The FISH test is also expensive and may not be covered by your insurance carrier because they look at it as a ‘preliminary test’ result.
· “How many days will I have to stay at bed rest? (usually phrased as “Can you give me a note for work for the next week?”)” – Unless there is a complication of the procedure, you will not have to go home to bed rest. We do recommend that you avoid heavy lifting and other exertional activities today and drink some extra fluids. If you think today will be a problem at work, we will give you a note.
· “What do I look for to suggest a problem” – Leakage of fluid, cramping, pain, bleeding, fever – It is not unusual to have a little cramping over the first 24-48 hours after the procedure and you can take Tylenol, or even a few doses of over-the-counter strength ibuprofen, for this, but if it continues longer than that, or if you develop any of the other problems, you need to let your doctor know.
· “When can we have sex again? (usually this one comes from the partner, and the woman is usually grateful when I jokingly answer “NEVER”)” – I usually recommend that you avoid intercourse for 48-72 hours – wait at least 24 hours after the cramping has gone away.
· “How will I get the results” – We will call you as soon as they come back from the laboratory. Do you want to know for sure if the baby is a boy or a girl?
After we have finished the procedure, I usually ask if there are any more questions, wish them the best on the outcome, and tell them that, hopefully, they won’t need to come back to see me again during the pregnancy!
Labels: amniocentesis
23 Comments:
At Fri Nov 02, 09:38:00 AM 2007,
Yongsuk said…
Dr. T --
I am 38 years old amd pregnant for the second time. I am scheduling to have an amnio with my regular Ob/Gyn. For my last pregnancy, I had one done by a perinatologist, which was routine for the Ob I was seeing at the time. The perinatologist was extremely experienced and efficient. I don't remember 100%, but I also don't remember having to have 2 days of bedrest.
Now, with my current Ob/Gyn, I am doing the amnio at 16 weeks (instead of at 15 weeks as with the perinatologist) and she prescribes 2 days of bedrest post procedure. She has done over 1000 amnios over a ten year period.
Should I feel at ease about doing an amnio with her and is her experience level considered very high?
Sorry for the boring questions. Just the kinds of things that unnecessrily plague mothers.
Thank you.
Ana
At Mon Nov 05, 05:14:00 PM 2007,
Kenneth F. Trofatter, Jr., MD, PhD said…
To yongsuk Nov 2: I cannot answer your question. The total number is not as important as the skill and complication rate of the person doing the procedure. Also, it is a lot different doing genetic amnios at 16 weeks than amnios for fetal lung maturity at 36-38 weeks. Under most circumstances, two days of bedrest are not necessary, although I know I tell my own patients not to do a lot of heavy exertional activity or have intercourse for 48-72 hours following their midtrimester amnios. By the way, another alternative is to have maternal serum screening done instead of jumping into an amniocentesis at 16 weeks, and following up with a 'targeted ultrasound' at 18-20 weeks. The combination of those two screening tests might reduce the risk sufficiently that you forego the amnio altogether! Just a thought! Anyway, good luck with things and thanks for reading. Dr T
At Sat Mar 15, 04:11:00 AM 2008,
Anonymous said…
I recently had the 1st trimester screening done. Stats are as following : NT: 2.6mm CRL : 59.3mm Gest Age : 12.3 # of fetuses: 1 Age at term : 39.4. The results from the NT plus blood work are as following : NT : 1.73 MoM PAPP-A: 1.29MoM hCG: 2.5MoM. I was given a screening risk of 1:10 for Down Syndrome and 1:5,000 for Trisomy 18. I did get a CVS done. The genetic counselor said that because of a high hCG level weighted with my age is the main reason why my risk for DS is high. In your experience how often does the result come back positive for DS with women who have similiar results as mine. thanks
At Fri Mar 21, 06:40:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Mar 15: As has been reprted to you, that combination of results gives you a risk of 1 in 10. The data bank used to generate that risk is far more vast than any individual's personal experience. Remember, you still have a 90% chance the baby does NOT have Down syndrome! Thanks for reading, good luck to you, and please let us know what you find out. Dr T
At Thu Mar 27, 11:14:00 AM 2008,
Anonymous said…
Is rest (eg no vigorous exercise) after amnio proven effective at preventing miscarriage or is it simply a conservative convention? I am 37, in good health, 2nd pregnancy, extremely active, working, and have a 3 year old to take care of - 'rest' doesn't exist in my life...please advise. Thanks.
At Thu Mar 27, 06:00:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Mar 27: I believe I answered your question yesterday on the post with your original comment. My concern in your case is that you do VERY vigorous exercise. Bedrest is not indicated but heavy exertion could increase the risk of rupturing membranes after an amnio. There is NO good data on this, but why don't you just take it a little easier for 24-48 hours afterwards to give the insertion site a chance to seal over. I have had perfectly healthy women lose perfectly normal babies because they wouldn't give up their intensive exercise routines during pregnancy! Good luck on all counts! Dr T
At Fri Jul 11, 02:42:00 AM 2008,
katja said…
Hi Dr T,
I had an amnio done 3 days ago, the procedure went fine and i'm ok, just some mild cramping. When are you considered to be 'safe' from miscarrige due to the amnio? My dr said the first 48 hrs are crucial, and then some can have an infection up to a month after the procedure. Does that seem right to you? I read some stories about women losing fluid and having infections even a month later. What are the reasons for that infection? Do the memranes close up themself or is it possible the hole doesn't close up at all?
Thank you, Kat
At Sat Jul 12, 08:53:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Kat: The first 48-72 hours are critical from the standpoint of rupturing membranes following an amnio, but the risk of infection does extend out about a month, although infection is remarkably rare following the procedure. Dr T
At Fri Jul 18, 12:04:00 PM 2008,
Chris said…
I had an amniocentesis at 16 weeks. I did not have any real cramping, fever, spotting, leaking of fluid after the amnio. At my 20 weeks ultrasound, I was told the baby had died in utero. The doctors blamed it on the amnio. The amnio showed that there were no chromosomal defects. If I lost the baby due to an infection, wouldn't I have had symptoms.
Also, if the baby hits the side of the needle, could this cause fetal demise and if it could, how long would it take for the fetus to die?
At Fri Jul 18, 06:48:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Chris July 18: What was the reason for having the amnio done?What size was the baby when it died (i.e, 16, 17, 18... weeks). It is unusual for a baby to die from a needle stick alone. Inadvertant laceration of the umbilical cord would be a more common cause. If the baby was found to be lost as the result of an infection, I have been truly amazed by how much infection can be 'hidden' inside the uterus without the mother having a fever, pain, or even an abnormal white blood count. I am so sorry for your loss, but please let us know what you find out. I know it is hard, but thank you for sharing your story. Amniocentesis does carry some risks. Dr T
At Sat Jul 19, 07:51:00 AM 2008,
Chris said…
I had the amnio because I was 37, and years earlier, I had lost a baby half way through my pregnancy due to Turner's syndrome. My first trimester screening came back great for Trisomy 21 and Trisomy 18. Given my history, my doctor told me it would be prudent to have the amnio.
The baby's femur showed no growth since having the amnio; however, I did feel fetal movement weeks after having the amnio.
After I had the D&E, the doctor said my white blood cell count was a little high, but said that could be due to being pregnant.
I really wasn't given any real info--the loss was attributed to the amnio because it occurred 30 days from having the amnio.
I really feel that they could have told me more. I have since gone on to have another baby who, as it turns out, has Down syndrome. I didn't have the amnio with that pregnancy, but all screening tests came back fine--until week 34 when the femur appeared to be shortened.
I guess I'm just looking for more definitive information. I feel like the doctors should have been able to tell me more than "oh it was the amnio". I guess I still want to know, why. What about the amnio caused the loss.
At Wed Jul 23, 11:24:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Chris: I am so sorry - you have had a rough time. The amnio certainly would have been something we recommended as well. If the baby was lost shortly after having it done, it may well have been the result of an unsuspected laceration of the umbilical cord or a fetal-placental blood vessel. If the placenta and the baby were evaluated by pathology, they should also have been able to tell you whether or not infection (chorioamnionitis) was present. I can understand the need to know, but unless some of that information is available, you might never get an answer. Again, I am so sorry for all the difficulties you have had. Dr T
At Wed Jul 23, 12:48:00 PM 2008,
Chris said…
As far as I know none of the tissues were examined by pathology after I had the D & E done. I asked if there was any way they could give me more info as to the cause of the fetal demise and was told "no". I would hope that if my doctors had any definitive info they would have given it to me. I appreciate I may never know what truly happened. As I said, I did go on to have another baby. Yes, he does have Down syndrome, but I must admit, the diagnosis still scares me, he is the sweetest baby around and very much like my other two "typical" children. If I had know then what I know now, I would never have had the amnio. Thank you for all of your kind words and advice.
At Wed Jul 23, 05:33:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
Chris: You're welcome and thanks again for reading! Dr T
At Sat Aug 30, 08:25:00 PM 2008,
Anonymous said…
Dr. T:
I am taking low dose aspirin after suffering 3 early unexplained miscarriages and would like to know at what point do you recommend I stop taking aspirin prior to the amniocentesis? Also, when can it be resummed after the procedure?
Have you found women taking low does aspirin have a greater chance of miscarriage/ complications after the amniocentisis? I am also concerned that by stopping the low dose aspirin for a period of time, will reduce blood flow to the uterus and potentially harm the baby. Any information that you could provide me with would be greatly appreciated.
Thank you.
Jennifer
At Tue Sep 02, 05:43:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Jennifer: The aspirin does not affect blood flow to the uterus, so don't worry about that. Aspirin inhibits platelet function and a single baby aspirin can have that affect for 48 to 72 hours. It does not affect the other side of the blood clotting system. I usually do not stop it for an amnio, but if there is an anterior placenta or you are worried about it, then stopping it a couple of days beforehand and resuming 12 hours after the amnio should provide a wide margin of safety for the procedure and not deleteriously affect the pregnancy. Good luck. Dr T
At Wed Sep 03, 08:53:00 PM 2008,
Paul said…
Dr. T,
We had an amniocentesis yesterday due to what appeared to be a symetric baby that was growth restricted by roughly two weeks. The doctor believes that there is a 50/50 chance that its a genetic issue. The question I have is the gestational age that they are trying to base this on was my wifes last period started April 23 2008.
However this was my wifes first period in over two years as a result of breast feeding. Her cycles were never normal when she was off the pill fluxuating as much as 5 to 7 days late. The first screening (ultra sound) we had on June 30, this estimated the baby's gestational age at 9 weeks 0 days. The one we had on 3Sep08, showed development consistent with that of a 15/16 week old fetus. So as of 3SEP08 they say we should be 19 weeks 0 days. Especially when I told them that I didn't even come into town until May 8th 2008, which would be gestational age 2 weeks 2 days. Is this correct that the gestation age would potentially be over 2 weeks before we even had the ability to copulate. And if the amniocentesis can't explain the delayed growth, what could, because the normal factors have been ruled out such as smoking, drugs, alcohol. Wife is 28 years and first baby was healthy. It just seems like a dating issue and not a issue that amnio will answer, and maybe fhe first ultro could have been off by 5 days or so, or is it more likely the baby is loosing 5 days roughly every 3 weeks.
Thanks,
Paul
At Wed Sep 03, 08:59:00 PM 2008,
Paul said…
I forgot to mention 2 things
My wife has a bicornuate uterus and complete placenta primavera, I think thats what it is called when it is fully blocking the opening.
That might help with diagnosis.
At Sun Sep 07, 09:48:00 PM 2008,
methetwholovesbabies said…
I have another question about amnio and more general pregnancy loss. This is long, I am sorry.
I am 38 [and 3 months] and just lost my third child at 19 weeks. Diagnosed at ultrasound. Two prior miscarriages, one at age 34 about 10weeks, another at 36-37 diagnosed at 10 weeks, but was blighted ovum. They then diagnosed a 5-6lb fibroid outside my uterus which they shrunk with Lupron and did successful myoectomy. No live children.
We then healed from surgery and became pregnant within 7 months after surgery[were advised to give 3 months for healing then try]. I was 37 at time of becoming pregnant, turned 38 2 months into it.
Pregnancy was good, I was very sick 1st trimester, which I thought was good sign. We went in for the second trimester ultrsound and found out our little boy had died. We had been watched very carefully by the fertility clinic and has positive ultrasounds at 6, 8, and 10 weeks. With lots of movement at 8 and 10 weeks.
After that 2nd trimeseter horrible ultraound, I allowed them to do an amnio. I had not allowed it prior because I wanted no risk. I had only allowed 1st trimester ultrasound and nuchal translucnecy which had been very good news.
Amnio results came back, baby boy was perfect- no chromosmal abnormalities.
I have a history of some weird auto immune issues, never really figured out. Husband and I are both attys with pretty high stress, at 33 I was daignosed with esophageal candidas, did every test known to mankind, no indication of Lupus, cancer AIDS, diabetes etc. Everything that normally causes this [they told me].
Since then, I get swollen lymph nodes both sides underarms eveyr 6 months or so, have constant itching in vaginal area and anal area, have had one 'positive' anticardiolipin blood test, but one fine.
We want at least one biological child more than anything, and then I want to adopt more, maybe special needs.
At this point, the psychological pain, and not wanting to do this to another baby if there is something wrong we do not understand is very strong. We are considering surrogacy considering the myoectomy, strang auotimmune, and no chromosomal amnio. I also want to freeze some embryos in case we can figure out what is going on in the meantime.
This has been 4 years and I am not willing to go through more. We can afford about 70K in surrogacy fees, and then we will not have savings, but will have 401K and be able to keep paying on mortgage, we will be fine.
At Tue Sep 23, 08:12:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To methetwho...: It is hard to say what is best in your situation at your age and with what you have been through because we do not know the cause of your midtrimester loss. You could try empiric therapy with aspirin and heparin or lovenox with or without low-dose prednisone on the chance that this is the result of an 'autoimmune' condition; and/or, IVF with embryo preservation in case you want to go the surrogacy route; or IVF with preimplantation genetic diagnosis for fetal chromosomal abnormalities. The surrogacy approach may be the best approach in view of the 'unknowns" and the complications you have had. Best wishes to you and I hope, whatever you choose, success in getting the family you want to have! Dr T
At Wed Oct 01, 01:08:00 PM 2008,
EH said…
I have just had an amnio and FISH results show a normal girl. I am currently 19 weeks and will be 40.6 at delivery. I understand FISH only tests for 13, 18, 21, and X,Y and is usually called a "preliminary" result. My question is: are the 13, 18, 21, and X,Y results ever reversed upon the full results? Or is it definitive for 13, 18, 21, and X,Y, and the reason it's called "preliminary" because of the myriad other things the full result will test for? Sincerely, EH
At Fri Oct 03, 12:06:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Paul: An ultrasound at 9 weeks should be accurate to within plus or minus 3-4 days, regardless of your wife's cycles. If the baby is that far behind, it could have a chromosomal abnormality, a genetic syndrome, an infection (the most common being with cytomegalovirus - CMV), or a very lousy implantation. The latter is certainly a possibility if your iwfe has a bicornuate uterus and a placenta previa. Unfortunately, none of the outcomes under any of these circumstances is usually good. Please let us know how things turn out and I wish you all the best. Dr T
At Wed Oct 08, 05:17:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To EH: Nothing is 100%. If FISH indicates one of those chromosomal abnormalities, it is highly likely to be accurate. Where differences most commonly arise between the preliminary result and the final karyotype are when the FISH appears "normal" but there is a chromosomal abnormality present that is not detected by FISH, where maternal cells are 'read' as the "normal result", and where there is chromosomal mosaicism (two populations of cells - one normal and one abnormal) present and the onl;y cells that were visualized by FISH were the normal ones. I have only had ANY of these discrepancies arise, so hopefully, you are in good shape. Let us know how things turn out! Best wishes, Dr T
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